Analysis Meeting Agreement The International Regulations for Preventing Collisions at Sea, 1972 prescribe the actions to be taken when two vessels meet in a narrow channel. Rule 9(b) of these regulations prescribes that a vessel less than 20 m in length shall not impede the passage of a vessel which can navigate only within a narrow channel or fairway. The draught of the INCAT 046 would have permitted her to navigate outside the Main Channel. However, the size of the INCAT 046 and the configuration of Yarmouth Harbour in the area of Bug Light, would have made such navigation unsafe. Because of this, the 17 m long LADY MEGAN II was required to not impede the passage of the INCAT 046. The Canadian modifications of these regulations prescribe the actions to be taken when two power-driven vessels meet in a narrow channel or fairway where there is a current or tidal stream. Rule 9(k)(i) prescribes that the vessel proceeding with the current or tidal stream shall be the stand-on vessel and shall propose the place of passage and indicate the side on which she intends to pass. The next paragraph of the same rule prescribes that the vessel proceeding against the current or tidal stream shall keep out of the way of the vessel proceeding with the current or tidal stream and hold as necessary to permit safe passage. The day of the occurrence, the moon was almost full and large tide ranges were expected. The collision happened one hour and 46 minutes after high tide. An ebbing current could be expected. In fact, after the collision occurred, the INCAT 046 took all way off and drifted. Her drifting speed was southerly (outbound) at two knots. The INCAT 046 was the stand-on vessel and the LADY MEGAN II the give-way vessel. As such, the INCAT 046 was to propose the place at which the vessels would pass and indicate on which side she intended to pass. Although the navigation team of the INCAT 046 did not specifically propose where the vessels would pass, the navigator initiated a call to LADY MEGAN II, following Fundy Traffic instruction. The information received on the bridge of the INCAT 046 was that the LADY MEGAN II intended to hold her position south of Bug Light. This agreement was acceptable to both vessels for a safe passage. A few minutes before reaching the agreed-upon position for the passing of the vessels, the skipper of the LADY MEGAN II initiated a call to inform the ferry that he had decided to change the meeting agreement. At this time, the INCAT 046 was already committed to the narrowest section of the Main Channel. Since the crew of the INCAT 046 did not have the authority to specifically forbid such a change of plan, they informed the fishing vessel, without objecting to the new passage agreement, that the catamaran should be ready to come around the turn near Bug Light in possibly about two minutes. The master of the INCAT 046 confirmed with the skipper of the LADY MEGAN II a port-to-port passing and manoeuvred his vessel beyond the western edge of the Main Channel. This was intended to allow maximum distance between the vessels at the time of the passing. The collision occurred about one minute following this last communication. Although the LADY MEGAN II had the INCAT 046 on her radar, the possible two minutes time interval communicated might have reinforced the decision of the skipper of the LADY MEGAN II to change the passage agreement. Place of Passage Both vessels initially agreed to meet south of Bug Light. The LADY MEGAN II was to hold off until the INCAT 046 had proceeded through the narrow channel and passed the bend around Bug Light. This place of passage was at a point where the Main Channel is 118 m wide and where the depth to the east of the channel would allow a vessel like the LADY MEGAN II to proceed in case of emergency. The second place of passage agreed to was north of Bug Light. This place is situated where the Main Channel is only 76 m wide. Also, the depth to the east of the Main Channel at that point did not allow the inbound fishing vessel to proceed outside the Main Channel in case of emergency. The INCAT 046 has a beam of 23.8 m and the LADY MEGAN II has a beam of 6.7 m. If the first passing agreement had been carried out, the maximum distance between the vessels at the time of the passing would have been 87.5 m. The second place of passage proposed gave a narrower berth between the vessels of 45.5 m. Also, the second place of passage agreed upon did not allow the inbound fishing vessel to proceed outside the Main Channel if necessary. Since the fishing vessel could not leave the Main Channel at the second place of passage, the skipper had to keep a margin of safety between the bank and the starboard side of his vessel, which further reduced the distance available between both vessels. Considering the above, the first agreed-upon passing place was safer than the place where the vessels met. Marine Communications and Traffic Services The role of the Marine Communications and Traffic Services is of providing information. Notice to Mariners number 25 states that there is no intention of the part of the Coast Guard to attempt to navigate or manoeuvre ships from a shore station and nothing in the Notice overrides the authority of the master of his responsibility for the safe navigation of his ship. Information passed to the master by MCTS is intended to assist him in the safe conduct of his ship. However, a MCTS officer may, under specific circumstances, issue a direction to a ship and the ship shall comply with a direction. At about the time of the occurrence, only the INCAT 046 and the LADY MEGAN II were reported in movement in Yarmouth Harbour warranting the issuance of directions. MCTS interacted with both vessels through the exchange of information only. The responsibility to navigate the vessels rested with their crews. Position of the Collision As previously mentioned, the INCAT 046 was equipped with an ECDIS, which receives navigational data from a DGPS. The DGPS is a positioning system with an accuracy of 10 m or better, 95 per cent of the time. There is no record of malfunction of the closest DGPS stations, nor of the INCAT 046's DGPS equipment, at the time of the occurrence. The ECDIS system recorded that the shore station signal was received by the DGPS and positions displayed were corrected to DGPS accuracy. The ECDIS system in use on board the INCAT 046 is a personal computer-(PC) based system that has the capability of automatically recording several days of past navigational data in memory. The data is recorded as received from the DGPS. It was possible to play back the track of the INCAT 046. The track shows the DGPS positions of the INCAT 046 at 10-second intervals for the day of the occurrence. The LADY MEGAN II was equipped with a PC loaded with an electronic charting system. This PC was receiving navigational data from a GPS. Although this system was also capable of recording track, it had not been configured to do so by the operator. This option was not selected the night of the occurrence; therefore, it was not possible to play back the fishing vessel's track for the 41 minutes prior to the collision. GPS receivers have the capability of saving in memory the last few positions received before they are turned off. The GPS of the LADY MEGAN II was also analysed. There were 10 positions saved in the GPS memory. The last position stored in the memory was the closest one to the collision's position. However, this last position--locating the LADY MEGAN II at 4348.79' N, 06608.63' W--does not appear, on close examination, to be totally accurate. This may be explained by the fact that the antenna of the LADY MEGAN II was damaged during the collision before power to the GPS was cut off. Although the two recovered positions were slightly different it should be noted that the INCAT 046 as well as the LADY MEGAN II were using radar for navigation. The DGPS positions confirm that the collision occurred on the western edge of the channel. Radar Detection The navigator and master of the INCAT 046 could see the LADY MEGAN II on radar. However, they could not make an automatic plot of the fishing vessel due to its close proximity to the navigational buoys. Furthermore, automatic plotting of a target vessel negotiating a bend in a narrow channel, at close proximity, would be at best of limited value. The navigator was watching the progress of the fishing vessel on his radar and estimating the fishing vessel's movement. The LADY MEGAN II was equipped with two radars. Both were in operation when she proceeded into the harbour. The Furuno radar model FR-1011 was set on a range of 1.5 nm. This range would not allow the operator to use the radar effectively for collision avoidance in a channel as narrow as the Main Channel of Yarmouth Harbour. The Furuno radar model 1830 was the preferred radar for navigation in close quarters situations. It was not possible to determine to what range this radar had been set at the time of the collision. However, a witness recalled having seen the echo of the INCAT 046 at the edge of the screen a few minutes before the collision. Because the distance between the vessels was about 0.75 nm at that time, it is most probable that the range of the radar was set to this distance. The INCAT 046 appeared as an echo about half an inch in diameter at the edge of the screen. This would indicate a strong echo return from the ferry. This echo return would be even more predominant as the target approached. Under such a condition, the phenomenon called side lobe effect would be experienced.[4] Two trials were performed on ships equipped with radars similar to the radar utilised by the LADY MEGAN II for close-quarters situations. During these trials, the radars of both vessels experienced side lobe effect. A few seconds before the collision, the LADY MEGAN II had Bug Light close on her starboard bow and the INCAT 046 dead ahead of the vessel. With those two large metal structures at close proximity, it is likely that the side lobe effect was present. This effect would have made the echoes lack in clarity, thus making it difficult to define the INCAT 046 on the radar screen of the LADY MEGAN II. However, due to the technical characteristics of the INCAT 046 radars and to the fact that the LADY MEGAN II was not a large target, the side lobe effect was not significant on the radars of the INCAT 046. During post-occurrence sea trials, both radars were observed to pick up targets big and small and to display them clearly. Speed Rule 6 of the International Regulations for Preventing Collisions at Sea, 1972 prescribes that every vessel shall at all times proceed at safe speed. However, the rules do not dictate at what speed a vessel should proceed but enumerate factors to be taken into account when determining a safe speed. Inter alia, the rules prescribe that all vessels should take into consideration the state of visibility, the traffic density and the manoeuvrability of the vessel. Also, vessels with operational radars must take into consideration, among other factors, the characteristics, efficiency and limitations of the radar equipment. The term safe speed is relative. Vessels must proceed at a speed safe for the existing conditions. If a vessel is involved in a collision, it does not necessarily mean that the vessel was proceeding at an unsafe speed. As conditions change, the speed considered safe for a particular vessel also changes. The speed of the INCAT 046 was set to 13.4 knots over the water at the departure from the dock and kept steady until the passage agreement was modified. When this occurred the speed was reduced to 9.2 knots over the water and was still decreasing when emergency actions were taken. At 9.2 knots, the fast ferry catamaran can stop, in case of emergency, in less than 111 m. The speed of the LADY MEGAN II was set to about 9 knots through the water (full speed ahead). At this speed, a small fishing vessel can stop in a short distance. Also, the only other traffic in the harbour, the INCAT 046, was visible on her radar. However, as both vessels approached each other, it is likely that the side lobe effect took place and the image on the radar screen of the LADY MEGAN II was not clear enough to allow the skipper to accurately determine the position of the INCAT 046. The conditions had deteriorated but the speed of the LADY MEGAN II was not reduced until emergency collision-avoidance action was taken. Visibility of Side Lights The side lights of the INCAT 046 are mounted at about mid-length of the vessel and 7.156 m above the waterline. From a position 100 m directly ahead of the vessel, the ship's sides do not allow an approaching vessel to see the INCAT 046 port and starboard side lights. The navigating personnel of the INCAT 046 were able to sight the running lights of the LADY MEGAN II a few seconds before the collision and immediately estimate her relative course. However, it was not possible for the crew of the LADY MEGAN II to sight the side lights of the INCAT 046 before the collision. In these close quarters circumstances, the fact that the crew of the INCAT 046 could see the side lights of the LADY MEGAN II means that the crew of the LADY MEGAN II latterly could not see the side lights of the INCAT 046 due to the design of the ship--and not because of bad visibility due to fog. Conclusions Findings Visibility was reduced in thick fog, and navigation was conducted primarily with radar. Both vessels had made radio contact and had agreed on a passing south of Bug Light. Shortly afterwards, the skipper of the LADY MEGAN II notified INCAT 046 of a change to the first passage agreement, which was acknowledged by INCAT 046. The engine setting of the LADY MEGAN II was full speed ahead, which gave the fishing vessel a speed of about 9 knots through the water. Speed was not reduced after the passage agreement was modified and conditions changed. The speed of the INCAT 046 was reduced to 9.2 knots through the water and the vessel was steered to the western edge of the Main Channel after the passage agreement was modified and conditions changed. It is likely that the radar of the LADY MEGANII was affected by the close quarters phenomenon of side lobes--making it difficult to determine the exact position, course and speed of the INCAT 046. It was not possible to determine to what range the radar used for navigation on the LADY MEGAN II was set at the time of the collision. There was more room for both vessels to manoeuvre south of Bug Light as per the first agreement reached, than north of Bug Light where the vessels collided. The LADY MEGAN II crossed over the 76 m wide channel and collided with the INCAT 046 at the western edge of the Main Channel. The crew of the LADY MEGAN II did not see the side lights of the INCAT 046 at any time, initially because of the existing visibility and subsequently because the fishing vessel was close to the bow of the catamaran where her lights, positioned on the outside of each hull, were not visible. The LADY MEGAN II and the INCAT 046 collided when the fishing vessel was steered across the Main Channel in the path of the ferry. Factors contributing to the accident were that the LADY MEGAN II did not adhere to either the original or second passing agreement and did not reduce speed when the conditions of navigation changed. Also, the INCAT 046 did not challenge the proposed second passage agreement.Causes and Contributing Factors The LADY MEGAN II and the INCAT 046 collided when the fishing vessel was steered across the Main Channel in the path of the ferry. Factors contributing to the accident were that the LADY MEGAN II did not adhere to either the original or second passing agreement and did not reduce speed when the conditions of navigation changed. Also, the INCAT 046 did not challenge the proposed second passage agreement.